It has previously been proposed to provide the gap-defining end of a ground electrode of a spark plug for internal combustion engines with two angularly spaced apart non-parallel prongs or arm portions, see U.S. Pat. Nos. 4,268,774 and 4,916,354. The prongs or arm portions are joined together at a base or vertex region to define a generally V-shaped configuration. The V-shaped prong configuration is so arranged and oriented relative to the center electrode of the spark plug to permit a spark to jump the gap between the center electrode and the ground electrode at the base or vertex region where the two prongs join together. Subsequently, the spark simultaneously travels along the two prongs. This simultaneous travel of the spark along the two angularly spaced apart non-parallel prongs is believed to be a major contributing factor to better mileage, less pollution in the engine exhaust and reduced carbon build-up on the electrodes.
However, previously known methods for forming spark plugs with ground electrodes of the type identified above are labor intensive and time consuming. Specifically, some previously known methods of forming the substantially V-shaped configuration in the gap-defining end of the ground electrode have required that the ground electrode first be straightened. Subsequently, the ground electrode is split into the two prongs. Once the two prongs are formed into the substantially V-shaped configuration, a corresponding portion of the ground electrode is bent over to form the gap-defining end. This method of forming the gap-defining end of the ground electrode is undesirable for a number of reasons. In this regard, it is noted that the additional bending steps can significantly weaken the ground electrode. Further, these additional bending steps significantly increase the time of manufacture.